Modern vehicles (so-called automobiles) are provided with various apparatuses for detecting the state thereof,
For example, as a low internal pressure alarm device for the tire, the direct type device which directly measures the internal pressure for issuing an alarm, and the indirect type device which detects a change in tire revolution speed resulting from a change in rolling radius due to a change in tire internal pressure for issuing an alarm have been developed.
However, the former uses radio wave for signal transmission to or from a revolving wheel, thus the power supply contained in the rotating element presents technical and durability problems, while the latter gives convenience including the device commonness to the ABS (anti-lock braking system), and the like, but any of the devices of this type has functions specified for the internal pressure of the tire, and is not a system which offers information including that about a change in running stability of the vehicle.
In addition, a system which is used in conjunction with the ABS, the TCS (traction control system), or the like, is difficult to accommodate a change when the tire is changed or when the characteristics of the suspension/chassis of the vehicle are changed, thus involving difficulties in adding the user's preference, such as a desired change of the tire, to the vehicle.
Although a contrivance for stabilizing the vehicle behavior by detecting the occurrence of a yaw moment in the vehicle, and combining the result with the braking of the wheels has been created, such a control falls in the category of control of a relatively large vehicle behavior, such as understeering or oversteering when turning, or the like, providing a mechanism which carries out control by detecting a change in yaw that is caused when the vehicle turning, and which primary object is to control after the occurrence of a yaw.
Further, a system which detects a change in a vehicle body acceleration to control the drive force distribution, and when the running stability of the vehicle is deteriorated, prevents such a phenomenon from proceeding, has been devised (TCS). Such a system is for stabilizing the attitude in cornering (for prevention of spinning, and the like), and is not for a technique in which, for the running stability in pseudo straight running within the minute steering angle region, which is frequently utilized in general running, with grasping a phenomenon of the source which causes a yaw to occur from the motion of the respective wheels, tendency thereof is monitored, or an alignment adjustment which causes the problem is related.
In addition, such a system aims at a control which covers a generated fluctuation in yaw and an occurred change in vehicle acceleration, on the presumption that the initial state of the vehicle varies from vehicle to vehicle. Thus, such a system does not reference to the initial state of the running stability of the vehicle for monitoring and maintaining it, and does not find a problem with a change in internal pressure, an alignment change, or the like.
In other words, the prior art has been only a measure against a phenomenon which has already occurred, and not an art which monitors the source for occurrence of a phenomenon to relate it to the necessity for repair or fault alarming.
Any vehicle can be checked for alignment by using an alignment tester, but the alignment tester cannot examine for fluctuation of the alignment of the vehicle in normal actual running.
In addition, no art has been available which, when the alignment has been changed due to some factor, such as a time dependent change (a change with passage of time), or the like, automatically adjusts the alignment such that the running stability of the vehicle is not deteriorated.
Further, a method is available which measures the magnitude of a lateral force by use of a platform tester, and adjusts the lateral force to be within the specified tolerance (reference range), but the method will not allow examining the fluctuation of the lateral force to the vehicle when the vehicle normal running.
The purpose of the present invention is to eliminate the drawbacks of the above-mentioned prior art, and to provide a vehicle state analyzing system, a vehicle, and a vehicle state management system which can grasp a problem of the state of a vehicle in normal running, such as the running stability related to the wheel mounting angle which depends on the characteristics of the tire, the time dependent change of the suspension/chassis or the change in adjustment of the suspension, the change in internal pressure of the tire, and the like.